Nowadays, the computing speed and the consumption power of the integrated circuit chipset installed within an electronic device are significantly increased. Consequently, during operations, the integrated circuit chipset may generate much heat. For avoiding the performance degradation and the burnt-out of the integrated circuit chipset, it is necessary to dissipate the heat immediately and effectively. Generally, a heat sink is used to dissipate the heat generated by the integrated circuit chipset. The heat sink is attached on a surface of the integrated circuit chipset. In addition, a locking device is used for securely fixing the heat sink on the integrated circuit chipset, so that the heat generated by the integrated circuit chipset can be transferred to the heat sink and then radiated to the surroundings.
For securely fixing the heat sink on the integrated circuit chipset, an adhesive thermal pad may be arranged between the heat sink and the integrated circuit chipset. Moreover, in response to a downward force exerted on the heat sink, a close contact between the heat sink and the integrated circuit chipset is achieved. Under this intended circumstance, the heat-dissipating efficacy of the heat sink is enhanced.
However, the use of the heat sink to remove the heat from the integrated circuit chipset in the conventional ways still has some drawbacks. For example, since the thickness of the integrated circuit chipset (or the total thickness of the integrated circuit chipset and the thermal pad) is varied according to the practical requirements, various locking devices are produced to comply with different thicknesses of different integrated circuit chipsets. The locking device has specified resilient arms and resilient points. That is, every kind of locking device is applied to an integrated circuit chipset with a corresponding thickness. Under this circumstance, the preparation cost and the stock cost are increased, and the stock management becomes complicated. Moreover, the contact pressure between the heat sink and the integrated circuit chipset fails to be adaptively adjusted according to the thickness of the integrated circuit chipset. If the contact pressure is insufficient or the tolerance is poor, the heat-dissipating efficacy is deteriorated. Whereas, if the contact pressure is too large, the integrated circuit chipset is possibly damaged.
Moreover, the layout space of the resilient arms and resilient points may decrease the heat-dissipating area of the heat sink, and thus the heat-dissipating efficacy is reduced. That is, the heat-dissipating area of the heat sink fails to be effectively utilized. In a case that the integrated circuit chipset is a ball grid array (BGA) chipset, the solder balls (i.e. the pins) of the chipset are very close to the periphery of the substrate. If the locking device for locking the periphery of the substrate is made of metallic material, the locking device is possibly contacted with the solder balls to result in a short-circuited problem. On the other hand, if the locking device is made of plastic material, the short-circuited problem is avoided but the heat sink and the integrated circuit chipset fail to be securely combined together.